Current transformer



May 15, 1928.

J. B. GIBBS ET AL.

CURRENT TRANSFORMER Filed Sept. 8. 1923 INVENTORS O orOn Jesse B. Gibbs. BY Gordon 4.50M.

ATTORNEY x I the section line 11-11 of Flg.

Patented May- 15, 1928.

CURRENT TRANSFORMER.

Application filed September 8, 1923. Serial No. 661,563.

Our invention relates to current trans-.

formers and more particularly to. current transformers adapted for outdoor use.

One object of our invention is to provide a current transformer which is adapted for outdoor installations.

Another object of our invention is to provide a current transformer of the through type with a suitable mounting clamp which also serves as a weather-proof housing for a portion of the transformer.

A further object of our invention is to provide a current transformer for outdoor use which comprises a unitary structure.

In the measurement of currents traversing large capacity circuits, it has been found necessary to adopt an indirect method which frequently consists in utilizing the line conductor for the primary Winding of a small transformer, then measuring the current traversing the secondary winding thereof,

and computing the'current traversing the primary conductor. Heretofore, the use of such current transformers has been limited 2 to indoor installations. We propose to provide a current transformer of the aboveindicated characteristics which is equally adapted for indoor or outdoor installations.

In the accompanying drawings,

Figure 1 is a View, partially in elevation and partially in section, of a current transformer embodying our invention.

Fig. 2 is a plan view thereof taken along Fig. 3 is a view, partially 1n elevation and partially in section, of a detail thereof.

In the several figures of the drawing, like reference numerals indicate similar arts.

In the preferred embodiment 0 our invention, a tube 1, which copper or brass, is provided for the reception of a conductor 2 which is adapted to pass therethrough. This tube is supported by a suitable .two-part clamping device 3 from any suitable stationary base. The tube 1 supports a plurality of insulators 4 that are of the orcelain weather-proof. type and are divi ed into an upper and lower group, which is placed the clamp 3. The

between clamp 3 terminates in a housing 5 in which is placed a core member 6 of the ring type.

About the core member 6 there is wound a spiral conductor 7 which terminates in suitis preferably of able leads 8 and 9 which extend out of the housing 5 through suitable insulating bushlngs 10. a The tube 1 is insulated from the several insulators 4 and the winding 7 by a bushing 11 of the condenser type. As is shown in Fig. 3, this bushing comprises a-coating of insulating material 12, such as micarta, which is of uniform diameter and substantia-ll the length of the tube 1. Within the insu ating material 12 are placed a number of layers of conductin material 13 to 17 inclusive, such as tin foil The length of these several layers decreases outwardly from the tube 1. At approximately the central portion of the bushing 11, there is placed a layer of spirally wound wire 18 which serves as a binder for the as a point of zero potential between the clamp 3 and the tube 1.

The clamp 3 is protected from flash-overs along the outer surface of the tube 1 by reason of the total surface length of the insulators 4.

\ In the operation of our invention, the con to the energization of the conductor. The leads 8 and 9 may be carried to any remote measuring instrument or relay.

It will thus be seen that we have devised a current transformerfor outdoor application in which the secondary winding is protected from the weather and from flash-overs. The supporting clamp for our current transformer also acts as a weather-proof housing for the secondary winding ,and the core member.

We do not wish to be restricted to the specific circuit connections or arrangement of parts herein set forth, as various modifications thereof may be effected without departing from the spirit and scope of our invention. We desire, therefore, that only such limitations shall be imposed as are indicated in the appended claims.

We claim as ourinvention:

1. An out-of-doorcurrent transformer comprising a metallic tube' for the reception of a line conductor, ascore member mounted on the tube, asecondary winding bushing, as well associated with the core member and a plurality of insulators disposed on the tube between the ends thereof and the core member.

2. An out-of-door current transformer comprising a metallic tube for the reception of a line conductor, a core member mounted on the tube, a secondary winding associated with the core member, a supporting and housing clamp surrounding a portion of the tube and the core member, and a plurality of insulators disposed on the tube between the ends thereof and the clamp.

3. The combination with a conductor, of a windin inductively related thereto, means for insu ating said conductor from said winding comprising a bushing disposed therebetween, and a weather-proof housing forsaid insulating means and winding, said housing comprisin rain-deflecting structure extending ,longitu inally of said conductor.

4. The combination with a conductor, of a winding inductively related thereto, means for insulating said conductor from said winding comprising a bushing disposed therebetween, and a weather-proof housing for said insulating means and winding, said housing comprising a series of spaced rain-deflecting structures extending longitudinally of said conductor.

5. The combination with a conductor, of a winding inductively related thereto, means for insulating said conductor from said winding comprising a bushing disposed therebetween, and a weather-proof housing for said insulating means and winding, said housing comprising insulating rain-deflectin structure extending dongitudinally ofsaid conductor.

- 6. The combination with a conductor, ofa winding inductively related thereto, means for insulating said conductor from said inductively related.

winding comprising a bushing disposed therebetween, a coil encircling said' bushlng adjacent said winding, and a weather-proof housing for said winding, bushing and'coil. 7. The combination with a housing com prising detachable members, former core and windin disposed within said housing, rain-deflecting structures extending in opposite directions from said housing, and a bushing disposed within said structures for the reception of a conductor with which said winding is inductively related.

8. The combination with a housing comprising detachable members, of a transformer core and winding, disposed, within said housing, weather-proof structures extending in opposite directions from said housing, a bushing disposed within said structures, a coil encircling said bushing adjacent said housing, within said bushing for the reception of a conductor withwhich said winding is inductively related. 1

9. The combination with a housing comprising detachable members, and means for securing said housing to a supporting member, of a transformer core and winding disposed within said housing, weather-proof structures extending in opposite directions from said housing, a condenser bushing disposed within said structures, a coil encircling said bushing adjacent said housing, and'atube of non-magnetic material disposed within said bushing for the reception of a conductor with which said winding is In testimony whereof, we have hereunto subscribed our names this 23rd day of August, 1923.

JESSE B. GIBBS. GORDON A. BURR.

of a trans-- and a tube disposed 

